The present invention relates to an ink-jet recording head driving method and an ink-jet recording device wherein a piezoelectric element is formed on a part of a pressure generating chamber communicating with a nozzle opening from which an ink droplet is jetted via a diaphragm and an ink droplet is jetted by the displacement of the piezoelectric element.
Typically, an ink-jet recording head includes a pressure generating chamber communicating with a nozzle opening from which an ink droplet is jetted. The ink-jet recording head comprises a diaphragm which is deformed by a piezoelectric element and ink in a pressure generating chamber is pressurized to jet an ink droplet from a nozzle opening. Two variations of this type of ink-jet recording head are known. One such device uses a method whereby a piezoelectric actuator is used in a longitudinal vibration mode in which a piezoelectric element is extended or contracted in an axial direction. A second type uses a method whereby a piezoelectric actuator is used in a flexural vibration mode.
In the former method, the volume of a pressure generating chamber can be varied by touching the end face of a piezoelectric element to a diaphragm and a head suitable for high density printing can be manufactured. However, a problem arises with this method in that it is difficult to cut each piezoelectric element in the required shape, that of the teeth of a comb. This particular shape is required due to the arrangement pitch of nozzle openings. Further, it is difficult to position and attach the cut piezoelectric element onto a pressure generating chamber as required, leading to further complications in the manufacturing process.
The second known method provides the advantage that a piezoelectric element can be fixed onto a diaphragm in a relatively simple process. In this process, a piezoelectric material is baked resulting in a piezoelectric material corresponding to the shape of a pressure generating chamber.
However, not withstanding the advantages provided by the second method, there is a problem in that a piezoelectric actuator in the flexural vibration mode requires a larger area for displacement than a piezoelectric actuator in the longitudinal vibration mode. Consequently, the volume of a pressure generating chamber is increased and the quantity of ink in a jetted ink droplet is also increased, resulting in difficulties in forming the minute ink drop sizes required in certain graphics printing applications.
Further, there is also a problem in that the vibration of a meniscus after an ink droplet is jetted effects the jetting of the next ink droplet. To solve such problems, a driving method wherein vibrations are inhibited has been proposed. However, there is a problem in that the whole driving method is extended and cannot correspond to high frequency printing.